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313 lines
7.5 KiB
C
313 lines
7.5 KiB
C
/** Copyright (c) 2009 Open Information Security Foundation
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*
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* \author Breno Silva <breno.silva@gmail.com>
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*/
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#include "suricata-common.h"
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#include "suricata.h"
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#include "decode.h"
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#include "detect.h"
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#include "flow-var.h"
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#include "decode-events.h"
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/* Need to get the DEvents[] array */
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#define DETECT_EVENTS
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#include "detect-decode-event.h"
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#include "util-unittest.h"
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#define PARSE_REGEX "\\S[0-9A-z_]+[.][A-z+]+$"
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static pcre *parse_regex;
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static pcre_extra *parse_regex_study;
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int DetectDecodeEventMatch (ThreadVars *, DetectEngineThreadCtx *, Packet *, Signature *, SigMatch *);
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int DetectDecodeEventSetup (DetectEngineCtx *, Signature *s, SigMatch *m, char *str);
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void DecodeEventRegisterTests(void);
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/**
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* \brief Registration function for decode-event: keyword
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*/
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void DetectDecodeEventRegister (void) {
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sigmatch_table[DETECT_DECODE_EVENT].name = "decode-event";
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sigmatch_table[DETECT_DECODE_EVENT].Match = DetectDecodeEventMatch;
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sigmatch_table[DETECT_DECODE_EVENT].Setup = DetectDecodeEventSetup;
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sigmatch_table[DETECT_DECODE_EVENT].Free = NULL;
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sigmatch_table[DETECT_DECODE_EVENT].RegisterTests = DecodeEventRegisterTests;
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const char *eb;
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int eo;
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int opts = 0;
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parse_regex = pcre_compile(PARSE_REGEX, opts, &eb, &eo, NULL);
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if(parse_regex == NULL)
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{
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printf("pcre compile of \"%s\" failed at offset %" PRId32 ": %s\n", PARSE_REGEX, eo, eb);
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goto error;
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}
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parse_regex_study = pcre_study(parse_regex, 0, &eb);
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if(eb != NULL)
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{
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printf("pcre study failed: %s\n", eb);
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goto error;
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}
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return;
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error:
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return;
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}
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/**
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* \brief This function is used to match decoder event flags set on a packet with those passed via decode-event:
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*
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* \param t pointer to thread vars
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* \param det_ctx pointer to the pattern matcher thread
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* \param p pointer to the current packet
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* \param s pointer to the Signature
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* \param m pointer to the sigmatch
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*
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* \retval 0 no match
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* \retval 1 match
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*/
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int DetectDecodeEventMatch (ThreadVars *t, DetectEngineThreadCtx *det_ctx, Packet *p, Signature *s, SigMatch *m)
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{
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int ret = 0;
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DetectDecodeEventData *de = (DetectDecodeEventData *)m->ctx;
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if(de && DECODER_ISSET_EVENT(p, de->event))
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return 1;
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return ret;
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}
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/**
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* \brief This function is used to parse decoder events options passed via decode-event: keyword
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*
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* \param rawstr Pointer to the user provided decode-event options
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*
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* \retval de pointer to DetectFlowData on success
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* \retval NULL on failure
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*/
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DetectDecodeEventData *DetectDecodeEventParse (char *rawstr)
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{
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int i;
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DetectDecodeEventData *de = NULL;
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#define MAX_SUBSTRINGS 30
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int ret = 0, res = 0, found = 0;
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int ov[MAX_SUBSTRINGS];
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ret = pcre_exec(parse_regex, parse_regex_study, rawstr, strlen(rawstr), 0, 0, ov, MAX_SUBSTRINGS);
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if (ret < 1) {
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goto error;
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}
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const char *str_ptr;
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res = pcre_get_substring((char *)rawstr, ov, MAX_SUBSTRINGS, 0, &str_ptr);
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if (res < 0) {
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goto error;
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}
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for(i = 0; DEvents[i].event_name != NULL; i++) {
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if((strncasecmp(DEvents[i].event_name,str_ptr,strlen(DEvents[i].event_name))) == 0) {
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found = 1;
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break;
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}
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}
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if(found == 0)
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goto error;
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de = malloc(sizeof(DetectDecodeEventData));
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if (de == NULL) {
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printf("DetectDecodeEventSetup malloc failed\n");
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goto error;
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}
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de->event = DEvents[i].code;
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return de;
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error:
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if (de) free(de);
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return NULL;
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}
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/**
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* \brief this function is used to add the parsed decode-event into the current signature
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*
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* \param de_ctx pointer to the Detection Engine Context
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* \param s pointer to the Current Signature
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* \param m pointer to the Current SigMatch
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* \param rawstr pointer to the user provided decode-event options
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*
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* \retval 0 on Success
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* \retval -1 on Failure
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*/
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int DetectDecodeEventSetup (DetectEngineCtx *de_ctx, Signature *s, SigMatch *m, char *rawstr)
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{
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DetectDecodeEventData *de = NULL;
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SigMatch *sm = NULL;
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de = DetectDecodeEventParse(rawstr);
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if (de == NULL)
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goto error;
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sm = SigMatchAlloc();
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if (sm == NULL)
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goto error;
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sm->type = DETECT_DECODE_EVENT;
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sm->ctx = (void *)de;
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SigMatchAppend(s,m,sm);
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return 0;
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error:
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if (de) free(de);
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if (sm) free(sm);
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return -1;
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}
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/**
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* \brief this function will free memory associated with DetectDecodeEventData
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*
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* \param de pointer to DetectDecodeEventData
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*/
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void DetectDecodeEventFree(DetectDecodeEventData *de) {
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if(de) free(de);
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}
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/*
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* ONLY TESTS BELOW THIS COMMENT
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*/
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#ifdef UNITTESTS
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/**
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* \test DecodeEventTestParse01 is a test for a valid decode-event value
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*/
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int DecodeEventTestParse01 (void) {
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DetectDecodeEventData *de = NULL;
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de = DetectDecodeEventParse("ipv4.pkt_too_small");
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if (de) {
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DetectDecodeEventFree(de);
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return 1;
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}
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return 0;
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}
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/**
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* \test DecodeEventTestParse02 is a test for a valid upper + lower case decode-event value
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*/
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int DecodeEventTestParse02 (void) {
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DetectDecodeEventData *de = NULL;
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de = DetectDecodeEventParse("PPP.pkt_too_small");
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if (de) {
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DetectDecodeEventFree(de);
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return 1;
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}
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return 0;
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}
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/**
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* \test DecodeEventTestParse03 is a test for a valid upper case decode-event value
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*/
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int DecodeEventTestParse03 (void) {
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DetectDecodeEventData *de = NULL;
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de = DetectDecodeEventParse("IPV6.PKT_TOO_SMALL");
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if (de) {
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DetectDecodeEventFree(de);
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return 1;
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}
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return 0;
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}
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/**
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* \test DecodeEventTestParse04 is a test for an invalid upper case decode-event value
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*/
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int DecodeEventTestParse04 (void) {
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DetectDecodeEventData *de = NULL;
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de = DetectDecodeEventParse("IPV6.INVALID_EVENT");
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if (de) {
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DetectDecodeEventFree(de);
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return 1;
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}
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return 0;
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}
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/**
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* \test DecodeEventTestParse05 is a test for an invalid char into the decode-event value
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*/
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int DecodeEventTestParse05 (void) {
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DetectDecodeEventData *de = NULL;
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de = DetectDecodeEventParse("IPV-6,INVALID_CHAR");
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if (de) {
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DetectDecodeEventFree(de);
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return 1;
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}
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return 0;
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}
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/**
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* \test DecodeEventTestParse06 is a test for match function with valid decode-event value
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*/
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int DecodeEventTestParse06 (void) {
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Packet p;
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ThreadVars tv;
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int ret = 0;
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DetectDecodeEventData *de = NULL;
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SigMatch *sm = NULL;
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memset(&tv, 0, sizeof(ThreadVars));
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memset(&p, 0, sizeof(Packet));
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DECODER_SET_EVENT(&p,PPP_PKT_TOO_SMALL);
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de = DetectDecodeEventParse("ppp.pkt_too_small");
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if (de == NULL)
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goto error;
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de->event = PPP_PKT_TOO_SMALL;
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sm = SigMatchAlloc();
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if (sm == NULL)
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goto error;
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sm->type = DETECT_DECODE_EVENT;
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sm->ctx = (void *)de;
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ret = DetectDecodeEventMatch(&tv,NULL,&p,NULL,sm);
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if(ret)
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return 1;
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error:
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if (de) free(de);
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if (sm) free(sm);
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return 0;
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}
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#endif /* UNITTESTS */
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/**
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* \brief this function registers unit tests for DecodeEvent
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*/
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void DecodeEventRegisterTests(void) {
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#ifdef UNITTESTS
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UtRegisterTest("DecodeEventTestParse01", DecodeEventTestParse01, 1);
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UtRegisterTest("DecodeEventTestParse02", DecodeEventTestParse02, 1);
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UtRegisterTest("DecodeEventTestParse03", DecodeEventTestParse03, 1);
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UtRegisterTest("DecodeEventTestParse04", DecodeEventTestParse04, 0);
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UtRegisterTest("DecodeEventTestParse05", DecodeEventTestParse05, 0);
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UtRegisterTest("DecodeEventTestParse06", DecodeEventTestParse06, 1);
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#endif /* UNITTESTS */
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}
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